There is an apparatus such as a so-called “set-top box”, for example, having at least two modes, i.e., a power-on mode and a standby mode. In the power-on mode, for example, all the power supply circuits included in the apparatus are alive. In the standby mode, for example, only one or some of the power supply circuits in the apparatus are alive for the purpose of saving energy consumption. In order to indicate to a user whether the apparatus is in the power-on mode or the standby mode, the apparatus may have mode indicators made of light emitting elements such as Light-Emitting Diodes (LED).
Such mode indicators can be controlled by, for example, General Purpose Input Output (GPIO) pins of a CPU. However, for this purpose, one set of GPIO pins of a CPU are used. Also, for controlling mode indicators, a CPU needs to have GPIO pins that are active even in a standby mode or an extra Micro Control Unit (MCU) that is active even in a standby mode.